Multipurpose bulldozer assembly

ABSTRACT

A bulldozer assembly having a C-shaped frame member having a pair of rearwardly extending arms pivotally connected to a tractor for movement between a raised and lowered position. A moldboard having a cutting blade is centrally supported at the front end of the frame member by a ball joint located midway between the arms. A pair of double-acting hydraulic cylinders are attached to each arm at substantially the same point and diverge forwardly for universal pivotal attachment to the moldboard and serve to move the latter about longitudinal, vertical and horizontal axes passing through the center of the ball joint.

, atent amniins 1 Mar. 114, 1972 [54] MlUL'lllPlUPUSE BULLDUZE 3,213,553 10/1965 Foy ..l72/804 AfiSEMLY 3,234,670 2/1966 Fryer et al. ..l72/803 3, 78 91970 T asdal ..172 809K [72] lnventor: .llanis Mazmrins, Macedonia, Ohio 529 6 e e I [73] Assignee: General Motors Corporation, Detroit, Primary Exa in -Rob rt E- Pul rey Mich. Assistant Examiner-Stephen C. Pellegrino [22] Filed: Nov. 19, 1969 Attorney-J. L. Carpenter and E. J. Brskup 21 App1.No.: 077,984 57 ABSTRACT A bulldozer assembly having a C-shaped frame member hav- [52] US. Cl ..l72/804, 172/805, 172/ 807 ing a pair of rearwardly extending arms pivotally connected to lllilt. Cl- 1 1 a [factor for movement between a raised and lowered posilFneldl (It Search tion A moldboard having a cutting blade is centrally sup- 172/807, 809, 276 ported at the front end of the frame member by a ball joint located midway between the arms. A pair of double-acting [56] References Cmd hydraulic cylinders are attached to each arm at substantially UNITED STATES PATENTS the same point and diverge forwardly for universal pivotal attachment to the moldboard and serve to move the latter about DlCkll'lSOll longitudinal vertical and horizontal axes passing through the 2,943,407 7/1967 Long center f the uj 3,002,300 10/1961 Turbyfill.. 3,157,099 11/1964 Ulrich ..172/804 X 2 Claims, 7 Drawing Figures PMENTHBMAR 1 & 1972 SHEET 2 UF 2 I N VEN Y )R 4 ATTORNEY MIJILTEUPIUUSE BULLDUZEM ASSEMBLY This invention relates to a multi-purpose bulldozer assembly which can be used with either rubber-tired or crawler tractors and permits the blade to be adjusted to various positions so as to facilitate production dozing.

Bulldozer blade assemblies of the type which this invention is directed to usually consist of a C-shaped frame, the arms of which are pivotally mounted to a tractor which carries either hydraulic or cable means for lowering and raising the C-frame to a dozing position and a carry position, respectively. In most cases, the moldboard is connected to the front part of the C- frame through some form of universal connection, and suitable adjustable screw jacks or hydraulic cylinders are positioned on the outboard sides of the C-frame and connected to the rear outer edge of the moldboard for angling, tilting and pitching the latter for various dozing operations. ll-Ieretofore, it has been common practice to have the front central portion of the Cframc support the moldboard at a point adjacent to the cutting blade so as to direct the pushing forces more closely in line with the cutting edge of the moldboard. One problem, however, with an arrangement of this sort is that the angling struts and tiltjacks are usually so located that when the moldboard is tilted about the longitudinal axis of the tractor so as to make one comer thereof lower than the other, the various parts of the bulldozer assembly are subjected to unduly large stress concentrations.

The present invention is intended to alleviate the abovementioned problem with multi-purpose bulldozer assemblies by having the moldboard centrally attached to the front end of the C-frame by a ball and socket joint which permits universal movement of the moldboard. At each side edge of the moldboard a pair of double-acting hydraulic cylinders are universally pivotally connected at spaced points and converge rearwardly for universal pivotal connection with a side arm of the C-frame at a substantially common point. The arrangement is such that when the cutting blade of the moldboard is in a horizontal position, the points of connection between the hydraulic cylinders and the moldboard are spaced equidistantly from the center of the ball and socket joint. Thus, by expansion of one pair of jacks on one side of the dozer assembly and contraction of the other pair of jacks on the other side, the moldboard can be angled about a vertical axis passing through the center of the ball joint to permit side casting of dirt to either side of the tractor. In addition, by alternate expansion and contraction of the jacks on each side of the moldboard the latter can be pitched forwardly or rearwardly about a horizontal axis passing through the center of the ball and socket joint. Finally, and most importantly, by suitable adjustment of the hydraulic cylinders, the moldboard can be tilted about a longitudinal axis passing through the center of the ball joint without subjecting the C-frame structure and other parts of the bulldozer assembly to undue stresses previously encountered with dozer assemblies of the type described above.

Accordingly, the objects of the present invention are to provide a bulldozer assembly having a moldboard which is supported by a ball and socket joint and can be pitched about a horizontal axis, angled about a vertical axis, and tilted about a longitudinal axis so as to permit the moldboard to be used for various dozing operations; to provide a bulldozer assembly in which a central portion of the moldboard is supported by a C- frame through a ball and socket joint and is movable to vari' ous positions about the ball joint through pairs of hydraulic cylinders connected adjacent each side edge of the moldboard and the C-frame at points equidistantly spaced from the center of the ball and socket joint; and to provide a bulldozer assembly which through the use of pairs of diverging double-acting hydraulic cylinders located adjacent each side edge of the moldboard permits a quick change in the attitude of the latter without imposing undue stresses on any of the components of the bulldozer assembly.

Other objects and advantages of the present invention will be apparent from the following detailed description when taken with the drawings in which:

FIG. 11 is an elevation view showing a tractor equipped with a bulldozer assembly made according to the invention;

FIG. 2 is a plan view of the tractor and bulldozer assembly shown in FIG. 11;

FIG. 3 is a front view of the tractor and bulldozer assembly of FIGS. 11 and 2 and, with phantom lines, shows the moldboard tilted to two positions about the longitudinal axis of the tractor;

FIG. 4 is a plan view of the bulldozer assembly showing the moldboard angled about a vertical axis;

FIG. 5 is a view showing the bulldozer assembly in the extreme lowered and raised positions;

FIG. 6 is an enlarged side elevation view of the ball joint connection between the moldboard and the C-frame of the bulldozer assembly, and

FIG. 7 is a plan view with parts broken away of the ball joint connection shown in FIG. 6.

Referring to the drawings and more particularly FIGS. 1 and 2 thereof, a rubber-tired tractor 10 is shown having an operators cab 12 located substantially midway between front and rear axles 14 and 116. An engine compartment 18 is provided in the rear end of the tractor while the front end thereof supports a bulldozer assembly 20 made according to the invention. In general, the bulldozer assembly Ztll includes a C- shaped frame member 22, the front end of which supports a transversely extending moldboard 24 through a ball and socket joint 25, while the rear end includes a pair of laterally spaced arms 26 and 2d, the ends of which are connected to ball members 30 and 32 respectively secured to outwardly extending supports 34 and 36 rigid with the tractor 10. A double-acting hydraulic cylinder 37 extends between a support trunnion 36 on the tractor and a conventional pin and ball type universal joint 39 on the frame member 22 and serves to raise the latter about a horizontal axis passing through the centers of the ball members 30 and 32. In addition, each arm 26, 26 of the frame member 22 supports upper and lower doubleacting hydraulic cylinders 46 and 42 which diverge forwardly for connection with the moldboard 24.

More specifically, the moldboard 24 is of a rectangular form, as seen in FIG. 3, and has the lower forward edge thereof provided with a transverse cutting blade 44 as is conventional. As best seen in FIGS. 6 and '7, the rear surface of the moldboard 24 is formed with a pocket 46 which accommodates horizontally split sleeve members 48 and 50 having spherical inner surfaces which form the socket portion of the ball and socket joint 25 which also includes a ball stud member 52 carried by the frame member 22 midway between the arms 26 and 26. An end collar 53 holds the sleeve members 48 and 56 within the pocket 46, As seen in FIGS. l and 3,

. the pocket 46 is located centrally of the vertical side edges of the moldboard 24 as well as the top and bottom thereof. Thus, as seen in FIG. 11, this arrangement permits the moldboard 24 to be centrally supported by the front end of the frame member 22 and also allows the arms 26 and 28 of the frame member 22 to be located in a plane which is substantially parallel to the ground 54 when the moldboard 24 is positioned in the lowered dozing position.

As alluded to hereinbefore, each side of the frame member 22 is provided with a pair of double-acting hydraulic cylinders 40am! 42. Each of the hydraulic cylinders 40, 42 is identical in size, and as seen in FIGS. 1, 2 and 6, the upper hydraulic cylinder 46 has the cylinder portion thereof universally pivotally connected to an upper part of the moldboard 24 by a conventional ball type joint 55 which includes a transverse pin 56 having a spherical bearing 58 mounted thereon. The lower hydraulic cylinder 42 has the cylinder portion thereof universally pivotally connected to the moldboard 24 adjacent the lower end by a similarly constructed ball type joint 60 which also includes a transverse pin supporting a spherical bearing. In addition, the piston rod members of the hydraulic cylinders 40 and 42 extend rearwardly for universal pivotal connection by pin and ball joints 64 and 66 to a support bracket 68 rigidly attached to the associated arm of the frame member 22. It will be noted that the pin and ball joints 64 and 66 joining the piston rods to the support bracket 68 are located closely adjacent to each other and substantially at the same point. For that matter, assuming proper clearances are available, the piston rods of the hydraulic cylinders 40 and 42 can be secured by a common universal joint to the frame member 22 without impairing the operability of this bulldozer assembly.

From the above, it should be apparent that the arrangement of the hydraulic cylinders 40 and 42 is such that the latter diverge forwardly for universal pivotal connection with the moldboard 24 at points which, as viewed in FIG. 1, are equidistantly spaced from the center of the ball portion of the ball stud 52. Moreover, a plane passing through the centers of the ball members 30 and 32 and the ball portion of the ball stud 52, forms equal angles with the longitudinal center axes of the hydraulic cylinders 40 and 42. This is an important aspect of this invention because as will be explained hereinafter, movement of the moldboard 24 to the various dozing positions is facilitated without imposing large stress concentrations in any of the components which make up the bulldozer assembly 20.

The operation of the bulldozer assembly described above is as follows: Assuming the moldboard 24 is positioned in the lower dozing position as shown in FIG. 1 and it is desired to angle the moldboard 24 about a vertical axis passing through the center of the ball and socket joint to either the full line position or phantom line position shown in FIG. 4, this can be accomplished by contracting the hydraulic cylinders 40 and 42 on one side of the frame member 22 and expanding the hydraulic cylinders 40 and 42 on the other side. On the other hand, if it is desired to pitch the moldboard 24 forwardly or rearwardly about a horizontal axis passing through the center of the ball and socket joint 25, this can be accomplished by expanding both upper hydraulic cylinders 40 while contracting both lower hydraulic cylinders 42 or vice versa. Finally, in order to tilt the moldboard 24 to either of the phantom line positions shown in FIG. 3, such movement can be realized by expanding the upper hydraulic cylinder 40 on one side of the frame member 22 while simultaneously expanding the lower hydraulic cylinder 42 on the other side the same amount. This will cause the moldboard 24 to rotate about a longitudinal axis passing through the ball and socket joint 25,without imposing unduly large stress concentrations in either the frame member 22, the moldboard 24, or any other part of the bulldozer assembly 20.

Various changes and modifications can be made in this construction without departing from the spirit of the invention. Such changes and modifications are contemplated by the inventor and he does not wish to be limited except by the scope of the appended claims.

I claim:

1. In combination with a tractor, a bulldozer assembly mounted at the front end of said tractor and including a C- shaped frame member having a pair of rearwardly extending arms supported for pivotal movement between a raised position and a lowered position about a horizontal axis extending transversely to the longitudinal axis of said tractor, a mold board having a cutting blade at the lower end thereof, a ball and socket joint universally connecting the rear portion of the moldboard to the front end of the C-shaped frame at a point midway between said arms, said ball and socket joint including a ball stud member fixed to said C-shaped frame and a spherical socket portion formed in said moldboard, a pair of identical double-acting hydraulic cylinders associated with each of said arms, means universally pivotally attaching one end of said hydraulic cylinders to each of said arms along the outer side thereof and at substantially the same point, means universally pivotally connecting the other end of said pair of doubleacting hydraulic cylinders to said moldboard at vertically spaced points equidistantly spaced from the center of the ball and socket joint when the leading edge of the cutting blade is located in a horizontal plane, said ball and socket joint and said ivotal su rt for the rearward] extendin C-sha fram arms lyiri g i n a horizontal plane which form s equalai i gles with the longitudinal centers of said double acting hydraulic cylinders, said hydraulic cylinders being selectively operable to cause said moldboard to be angled about a vertical axis, tilted about a longitudinal axis, and pitched about a horizontal axis, and a double-acting hydraulic cylinder pivotally connected between the tractor and the C-shaped frame along said longitudinal axis for moving the latter between said raised and lowered positions.

2. In combination with a tractor, a bulldozer assembly mounted at the front end of said tractor and including a C- shaped frame member having a pair of rearwardly extending arms supported for pivotal movement between a raised position and a lowered position about a horizontal axis extending transversely to the longitudinal axis of said tractor, a moldboard having a cutting blade at the lower end thereof, a ball and socket joint connecting the center of the rear portion of the moldboard to the front end of the C-shaped frame at a point midway between said arms, a pair of identical doubleacting hydraulic cylinders associated with each of said arms, first ball type joints universally pivotally attaching one end of said hydraulic cylinders to each of said arms along the outer side thereof in a manner whereby the longitudinal center axes of the hydraulic cylinders intersect at a point which lies .in a plane passing through said horizontal axis and the center of the ball and socket joint, second ball type joints universally pivotally connecting the other end of said pair of double-acting hydraulic cylinders to the rear of said moldboard at vertically spaced points equidistantly spaced from the center of the ball and socket joint when the leading edge of the cutting blade is located in a horizontal plane, said hydraulic cylinders being selectively operable to cause said moldboard to be moved about vertical, longitudinal, and horizontal axes passing through the center of the ball and socket joint, and a double-acting hydraulic cylinder pivotally connected between the tractor and the C-shaped frame along said longitudinal axis for moving the latter between said raised and lowered positions. 

1. In combination with a tractor, a bulldozer assembly mounted at the front end of said tractor and including a C-shaped frame member having a pair of rearwardly extending arms supported for pivotal movement between a raised position and a lowered position about a horizontal axis extending transversely to the longitudinal axis of said tractor, a moldboard having a cutting blade at the lower end thereof, a ball and socket joint universally connecting the rear portion of the moldboard to the front end of the C-shaped frame at a point midway between said arms, said ball and socket joint including a ball stud member fixed to said C-shaped frame and a spherical socket portion formed in said moldboard, a pair of identical double-acting hydraulic cylinders associated with each of said arms, means universally pivotally attaching one end of said hydraulic cylinders to each of said arms along the outer side thereof and at substantially the same point, means universally pivotally connecting the other end of said pair of double-acting hydraulic cylinders to said moldboard at vertically spaced points equidistantly spaced from the center of the ball and socket joint when the leading edge of the cutting blade is located in a horizontal plane, said ball and socket joint and said pivotal support for the rearwardly extending C-shaped frame arms lying in a horizontal plane which forms equal angles with the longitudinal centers of said double acting hydraulic cylinders, said hydraulic cylinders being selectively operable to cause said moldboard to be angled about a vertical axis, tilted about a longitudinal axis, and pitched about a horizontal axis, and a double-acting hydraulic cylinder pivotally connected between the tractor and the C-shaped frame along said longitudinal axis for moving the latter between said raised and lowered positions.
 2. In combination with a tractor, a bulldozer assembly mounted at the front end of said tractor and including a C-shaped frame member having a pair of rearwardly extending arms supported for pivotal movement between a raised position and a lowered position about a horizontal axis extending transversely to the longitudinal axis of said tractor, a moldboard having a cutting blade at the lower end thereof, a ball and socket joint connecting the center of the rear portion of the moldboard to the front end of the C-shaped frame at a point midway between said arms, a pair of identical double-acting hydraulic cylinders associated with each of said arms, first ball type joints universally pivotally attaching one end of said hydraulic cylinders to each of said arms along the outer side thereof in a manner whereby the longitudinal center axes of the hydraulic cylinders intersect at a point which lies in a plane passing through said horizontal axis and the center of the ball and socket joint, second ball type joints universally pivotally connecting the other end of said pair of double-acting hydraulic cylinders to the rear of said moldboard at vertically spaced points equidistantly spaced from the center of the ball and socket joint when the leading edge of the cutting blade is located in a horizontal plane, said hydraulic cylinders being selectively operable to cause said moldboard to be moved about vertical, longitudinal, and horizontal axes passing through the center of the ball and socket joint, and a double-acting hydraulic cylinder pivotally connected between the tractor and the C-shaped frame along said longitudinal axis for moving the latter between said raised and lowered positions. 